Update test status and fix a typo.

dart/frog/tests/leg_only/src/CompileTimeConstant4Test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 final x = "foo";
 final y = "foo";
 final g1 = x + "bar";
 final g2 = x
   + null   /// 01: compile-time error
 ;
 final g3 = x
   + 499   /// 02: compile-time error
 ;
 final g4 = x
   + 3.3   /// 03: compile-time error
 ;
 final g5 = x
   + true   /// 04: compile-time error
 ;
 final g6 = x
   + false   /// 05: compile-time error
 ;
 final g7 = "foo"
-  + x[0];   /// 06: compile-time error
+  + x[0]   /// 06: compile-time error
 ;
 final g8 = 1
   + x.length  /// 07: compile-time error
 ;
 final g9 = x == y;
 
 use(x) => x;
 
 main() {
   Expect.equals("foobar", g1);
   Expect.isTrue(g9);
   use(g2);
   use(g3);
   use(g4);
   use(g5);
   use(g6);
   use(g7);
   use(g8);
 }